This invention relates to a suspension support disposed at an attachment portion of a buffer to a vehicle.
In general, in a suspension system of an automobile, etc., a so-called suspension support is disposed at an attachment portion of a buffer to a vehicle body, in order to control vibration, etc. transferred from wheels to the vehicle body.
FIGS. 9 and 10 show an example of the suspension support. FIG. 9 is a bottom plan view of the suspension support. FIG. 10 is a sectional-view taken along the line Axe2x80x94A of FIG. 9. The suspension support comprises an inner cylinder 101 made of steel in which a piston rod of the buffer is inserted and secured, an outer cylinder 102 made of steel attached to the vehicle body side, and a rubber elastomer 103 interposed between the inner and outer cylinders to dampen input vibration. The outer cylinder 102 is made up of outer circumferential flanges 106, 107, which are molded in one piece by spot welding 108, of upper and lower fittings 104, 105 that serve to axially compress the rubber elastomer 103.
Incidentally, in order to reduce energy consumption of automobiles in recent years, countermeasures against a weight reduction of each component have been required. Accordingly, it is also required to reduce the weight of the suspension support and the like.
The present invention is intended to reduce weight of the suspension support comprising the aforementioned inner cylinder, outer cylinder and rubber elastomer by making use of an outer cylinder made of aluminum, instead of conventional steel outer cylinder.
However, as for the suspension support of the type that holds the rubber elastomer vertically between the upper and lower fittings the cost of material will becomes dear only by changing the upper and lower fittings into aluminum ones. On the other hand, in case where the upper and lower fittings are molded in one piece, it is difficult to hold the rubber elastomer between both fittings molded as it is.
Therefore, according to the invention, the aforementioned outer cylinder is molded in one piece of aluminum into a shape with a cylindrical portion enveloping the rubber elastomer, an inner circumferential flange formed inwardly in the direction perpendicular to the axial direction at one axial side of the cylindrical portion, and an opening capable of inserting the rubber elastomer at the other axial side of the cylindrical portion, and the aforementioned rubber elastomer is axially held between the opening circumferential edge inwardly folded and formed by post-working and the inner circumferential flange.
The outer cylinder made of aluminum with good workability can easily be formed according to the folding working. Besides, due to reduction in the number of components and omission of spot welding process, reduction of production costs can be materialized more than making up for drawbacks of costly materials. Furthermore, the wall thickness of the outer cylinder must be made thicker to secure the same strength as that of the steel outer cylinder. But the thicker the wall thickness, the more the outer cylinder will be contributable to damping.
In addition, if the inner cylinder is also made of aluminum, the weight of the suspension support can further be reduced.
If there exist irregularities at the axial ends of the rubber elastomer, beating sounds generated when the rubber elastomer comes in contact with the inner circumferential flange of the outer cylinder can be avoided. That is, in case where the axial ends of the rubber elastomer is flat, an opening is left between the rubber elastomer and the outer cylinder when a large load is transferred at the time of bounding and rebounding, which may cause large beating sounds at the time of restoration when the rubber elastomer in conjunction with the outer cylinder is pressed against the inner circumferential flange.
On the contrary, when a convex portion is formed on the axial ends of the rubber elastomer and the convex portion is kept always in contact with the inner circumferential flange, a large load is gradually absorbed and damped, thus it is possible to prevent beating sounds effectively.